A rotor conventionally comprises at least one moving blade row having a plurality of moving blades which are arranged so as to be spaced apart from one another in the circumferential direction with respect to an axis of rotation of the rotor. In this case, the moving blades project from the rotor into a gas path. A working gas flows in this gas path when the turbomachine is in operation. Furthermore, such a rotor typically comprises a rotor shaft which has for the respective moving blade row a reception slot which extends in the circumferential direction and into which the moving blades are inserted with their blade roots. Furthermore, a plurality of intermediate pieces may be provided, which are arranged in the reception slot in each case between two adjacent moving blades.
Moreover, the moving blades have in each case a blade leaf which projects from the associated blade root, via which the respective moving blade is fastened to the rotor shaft, essentially radially away from the rotor and which thus protrudes into the gas path. In the region of an inner end portion assigned to the blade root, particularly in the case of a compressor, stabilization of the gas flow when the turbomachine is in operation can be achieved by means of special contouring on a rotor outer face adjacent to the blade leaf and exposed to the gas path. This contouring is a rotor end wall contour which delimits the gas path and which, in particular, may be curved along the gas path. In this case, it is basically possible to equip the moving blades at their blade roots, on an outer face confronting the gas path, with such a curved end wall contour next to the blade leaf in the circumferential direction.
For example, the drawings of U.S. Pat. No. 5,232,348 A and of U.S. Pat. No. 2,916,257 A show curved end wall contours, the gas path-side end walls of the intermediate pieces merging flush, and free of steps, into the end walls of the blade roots. Instead of the curvature having, confronting the gas path, a configuration which is convex, a rectilinear configuration may also be provided.